On 8/13/2013 1:02 PM, Charles Marcus wrote: >> You don't appear to have SPF nor DKIM configured. While in no way >> required, those do give some assurance that the mail is not forged, >> and may help. Or may not help, since you don't really know why >> outlook is complaining. > > Hmmm... so this would need to be done by our anti-spam provider > (since they are our mx *and* outbound relay), correct? >
You should be able to add these without involving your provider. Note: SPF is somewhat controversial, and discussion of its merits is a banned topic here. See archives/google for details. SPF is a special DNS record that you add to your own dns, specifying which servers may send mail purporting to be from your domain. This requires no modifications to the mail servers themselves. (Validating SPF on incoming mail is a separate issue; your anti-spam provider probably already does this for you.) https://en.wikipedia.org/wiki/Sender_Policy_Framework http://www.openspf.org/ DKIM is a crytographic header added to outgoing mail, proving the mail is from your domain and hasn't been altered. This can be added by your local server before it goes to the provider, or the provider may have a system in place to do this for you. This may require some modifications to your server config. https://en.wikipedia.org/wiki/Dkim http://opendkim.org/ of if you already use amavisd-new: http://www.ijs.si/software/amavisd/amavisd-new-docs.html#dkim -- Noel Jones
